(1) Field of the Invention
The invention relates to a vane diffuser for separating a gas/liquid/particulate-mixture flow in essentially a gas phase fraction and a liquid/particulate phase fraction, comprising: a distribution chamber holding a plurality of curved vanes lancing the side walls of the distribution chamber, the side walls being provided with passages between the curved vanes connecting the interior of the distribution chamber with the outside; and an inlet for the gas/liquid/particulate-mixture connecting to the distribution chamber. The invention also relates a method for introducing a gas/liquid/particulate-mixture in a separator.
(2) Description of Related Art
Vane diffusers are known in the technology field of extraction of hydrocarbons (oil and gas). For the further processing of voluminous gas flows containing liquids (e.g. oil and water) and/or solid particulate material (e.g. sand) different phases are separated from each other. The separation is conducted in several steps of which at the start of the separation process a rough separation step is conducted by leading the gas/liquid/particulate-mixture in a large separator (vessel) that may be horizontal or vertical positioned. In the context of the present invention a gas/liquid/particulate-mixture flow is considered to be a gas flow containing at least one of both: liquid particles or solid particulate material. However normally the gas/liquid/particulate-mixture to be processed contains both liquid particles and solid particulate material.
The initial separation process in the separator is realised by gravity. Larger droplets and particles will fall down into a reservoir in the lower part of the separator and the gas with remaining (smaller) droplets and smaller solid particles will flow upwards into the separator to a so called “calm zone” or “settling zone”. From the calm zone additional droplets and particles will fall down or flow down along the wall of the separator. The liquid and particles in the reservoir in the lower part of the separator will be extracted via a heavy fraction outlet located in the lower part of the separator while the gas (including still remaining droplets and particles) will be extracted on the upper side from the separator. Both the extracted (roughly separated) material fractions are normally further processed in different more thorough subsequent separation processes. It is also possible that one or more of such subsequent separation process steps also take place in the separator (e.g. by incorporating a coalescer in the upper part of the separator). The gas/liquid/particulate-mixture is normally introduced more or less at the middle of the separator through an inlet conduit. To distribute the gas/liquid/particulate-flow equally over the cross-section of the separator use is made of flow dividers like “baffle plates” and “vane diffusers”. The prior art dividers function well but are however limited in their capacity; as in separators of the introductorily disclosed type the capacity of the flow dividers are the bottle neck. When a flow divider is overloaded the maximum allowable flow rates of gas is exceeded resulting in significant volumes of liquid and particles being drawn up to the upward zone of the separator.
A general object of the invention is to provide a vane diffusers and a method for introducing a gas/liquid/particulate-mixture in a separator for efficient pre-separation of the gas/liquid/particulate-mixture in essentially a light, essentially gas containing, fraction and a heavier, essentially a liquid and particles containing, fraction with higher separation efficiency than the prior art diffuser technique by enhancing the maximum load (maximum capacity) of the diffuser before being overloaded.